Abstract [en]

The diverse butterfly subtribe Euptychiina was thought to be restricted to the Americas. However, there is mounting evidence for the Oriental Palaeonympha opalina being part of Euptychiina and thus a disjunct distribution between it (in eastern Asia) and its sister taxon (in eastern North America). Such a disjunct distribution in both eastern Asia and eastern North America has never been reported for any butterfly taxon. We used 4447 bp of DNA sequences from one mitochondrial gene and four nuclear genes for 102 Euptychiina taxa to obtain a phylogenetic hypothesis of the subtribe, estimate dates of origin and diversifica- tion for major clades and perform a biogeographic analysis. Euptychiina originated 31 Ma in South America. Early Euptychiina dispersed from North to South America via the tem- porary connection known as GAARlandia during Eocene–Oligocene times. The current disjunct distribution of the Oriental Palaeonympha opalina is the result of a northbound dis- persal of a lineage from South America into eastern Asia via North America. The common ancestor of Palaeonympha and its sister taxon Megisto inhabited the continuous forest belt across North Asia and North America, which was connected by Beringia. The closure of this connection caused the split between Palaeonympha and Megisto around 13 Ma and the severe extinctions in western North America because of the climatic changes of the Late Miocene (from 13.5 Ma onwards) resulted in the classic ‘eastern Asia and eastern North America’ disjunct distribution.

Peña, Carlos

Stockholm University, Faculty of Science, Department of Zoology.

2009 (English)Doctoral thesis, comprehensive summary (Other academic)

Abstract [en]

I present an overview of the evolutionary history of Satyrinae butterﬂies (Lepidoptera: Nymphalidae). By using Bayesian and cladistic methods, I develop a phylogenetic hypothesis as a basis for studying the evolutionary history of the group. After estimating ages of origin and diversiﬁcation for clades of interest, I show evidence for a radiation of a highly species-rich group of grass feeders in Satyrinae —the tribe Satyrini— which explains in part the high diversity of this group. The timing of diversiﬁcation for Satyrini butterﬂies coincided with the spread of grasses throughout the globe, which was followed by spread of the butterﬂies and colonization of new emerging habitats made available by the change in global climate during the Oligocene that facilitated the spread of grasses. Such a dispersal of Satyrinae was the result of a habitat shift from closed, forested environments into open, grasslands and savannas, which became increasinly common since the Oligocene. Such dispersal of Satyrinae was facilitated by the appearance of geographic bridges that permitted ancestral migrations from the Palaearctic into North America and from North to South America, such as the continuous forest belt of Beringia (at 31 Mya and 14–10 Mya) and the temporary GAARlandia landspan (during 35–33 Mya). Thus, I show that the Satyrinae butterﬂies are such a highly diverse and distributed worldwide group of organisms thanks to many factors that were of crucial importance in their evolution. Intrisic factors such as evolution of adaptive traits and phylogenetic constrains, as well as exogenous contingencies such as climate change and geological events. Thus, in this thesis I show strong evidence that Satyrinae is so species-rich because they were able to feed on grasses, escape from living in dicotyledonous forests and start inhabiting grasslands and savannas.

Research subject

Identifiers

Public defence

Opponent

Page, Roderic

University of Glasgow.

Supervisors

Wahlberg, Niklas

Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
Available from: 2009-02-19 Created: 2009-02-05 Last updated: 2011-03-22Bibliographically approved